***In my [last article](https://steemit.com/technology/@krishtopa/firewall-protection-from-hackers-viruses-and-especially-from-yourself-continue-to-acquaint-you-with-internet-technologies), I told you about Firewall and how it helps to protect your computer. Today I would like to share with you some information about another important component of computers security - Antivirus software.***

*The computer that does not have antivirus protection is at risk of malware infection. Modern viruses are so inconspicuous that the user can not immediately notice that his computer is infected. Quite often we think about the installation of the protection only after our computer got a virus that completely put it out of action. In order to properly select an antivirus program from a plurality of those offered by the market, it is necessary to understand how they work.*

![](https://i.imgur.com/GKPuaS2.jpg)

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# **Antivirus** - is a program which aim is to find and neutralize the viruses on the user's computer.

*First of all, I would like to say that the attempt to find and neutralize viruses manually is absolutely useless. Why?*

**Firstly**, you can’t know and most often do not know about the presence of viruses on your computer.

![](https://i.imgur.com/9adzEGh.jpg)

**Secondly**, if you find a suspicious object on the computer and it will be a virus and you try to remove it as a normal program then it won’t lead to something good. The virus usually still live somewhere on the computer and continues to harm your computer.


The most reliable and the most common way to protect it from viruses - it's antivirus software.

# There are three stages of Antivirus work:

1.    **Diagnostics**

Anti-Virus scans all available places that can be used by viruses on your hard disk, and if it finds a virus, it notifies you about this.

![](https://i.imgur.com/8QCrj8h.jpg)

2.    **Treatment**

As the virus is found - antivirus software can (user must choose):

-    Try to cure the infected file.

-    Place It in quarantine. That is, if the file is valuable for you and contains some important information, it can be placed in a quarantine folder. In the future, you can try to cure it "manually" by yourself or with the help of a specialist.

-    Delete the infected file. If the treatment was not possible, it is either hopelessly damaged by a virus or it became a virus itself. 

-    You can do nothing . Sometimes, antivirus gives a false alarm, and if you are sure that the scanned file is not a virus, then you can safely ignore your virus scanner.

3.    **Prevention**

Complete anti-virus software usually protects your computer permanently. That is, starts with the launch of the operating system and check viruses in every application and if it contains a virus or causes any suspicion, the antivirus immediately gives you an information about it, and then offer you decide what to do with this program: cure or quarantine or delete it from your computer or continue working without taking any action.

# The principle of antivirus work

Firstly, each computer antivirus contains antivirus database, it knows every virus (almost all). 

![](https://i.imgur.com/G0JP8eu.gif)

When using antivirus (checking files), anti-virus checks all scanned files and compare with its database, and if it finds a suspicious file, it immediately activates “alarm”.


Anti-virus database is being always updated. It updates very often, sometimes even several times a day, because every day there are so many new viruses; which must be recorded in the anti-virus database.

![](https://i.imgur.com/CO3rwpZ.jpg)

Secondly, there is the heuristic method of determining the virus. Antivirus analyzes programs and if it sees any suspicious piece of code, it also warns you about this, but there is certainly not impossible to give the 100% guarantee that this or another suspicious program is a real virus, so there may be some errors, but still very often these suspicious programs are malicious.

*And finally, of course, it is necessary to mention that anti-virus software usually provides several testing modes.*

# Usually, there are three testing modes:

- The maximum level of protection ensures maximum protection, but usually at the same time consumes a significant amount of computer resources. In this mode, the computer work considerably slows down.

- The average level of protection. It does not slow down your computer and at the same time provides an adequate level of protection, it is recommended for daily work. 

- The minimum level of protection. Generally, it includes verification on the basis of the anti-virus database, so it would warn you only if it is really 100% virus.

![](https://i.imgur.com/lWGBOxq.jpg)

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*There are a lot of types of viruses and they are upgraded every day and maybe even every hour. Fortunately, antivirus products are also improving their methods of protection using advanced programming languages. However, the threat of virus attacks remains relevant, especially given the fact that the number of viruses that are protected from copying would increase in few years. So you see that it is really important to install a good antivirus on your computer to defend it from malware.*

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**With Love,
Kate**

Image credit: [1](http://www.ldpalaos.org/is-the-crime-rate-high-in-your-neighborhood/), [2](http://cyberfort.blogspot.ru/2013/06/how-antivirus-software-works.html), [3](http://www.engineersgarage.com/comment/11394), [4](http://old.chinookwebs.com/email_security_overview.asp), [5](http://flylib.com/books/en/2.282.1.26/1/), [6](http://www.anti-virus-free.ru), [7](https://www.techmesto.com/4-best-antivirus-software-2016/)